Airports must manage the movement of a wide variety of apparatuses along the ground throughout an airport campus, for example including aircraft such as airplanes, gliders and helicopters, as well as ground vehicles such as automobiles, trucks, baggage carts, and fire suppression equipment. Effective and safe orchestration of airport ground traffic is critical in preventing aircraft collisions and other accidents. Large losses of life have occurred in airplane collisions caused by airplanes taking wrong turns while taxiing and into the path of another airplane, or by taking-off from the wrong runway and into another airplane. Collisions may be caused by many factors, but commonly at least one pilot is mistaken as to his airplane location relative to an actual approved runway or airport ground location. Moreover, when such a mistake occurs airport ground traffic controllers are usually not aware of the actual locations or destinations of the colliding planes and/or are unable to timely issue instructions to the involved pilots to thereby enable them to avert a collision.
It is proposed to incorporate ground microwave or radar devices in airports in order to enable detection and tracking of ground traffic. However, proposed approaches generally require a plurality of expensive radar or microwave devices, and even then due to high costs and other factors only enough devices are proposed to provide limited airport area coverage, typically at runway entrance points. Moreover, such ground radar systems are generally configured to provide airplane location information only to the airport ground controllers, not to aircraft pilots or vehicle drivers, each of which retains significant responsibility for decisions about aircraft movement at the airport.
Moreover, ground radar systems may not identify aircraft or vehicles with specificity, or they may not effectively distinguish between one or a plurality of individual aircraft or vehicles located in close proximity to each other, thus resulting in misreporting or omission of aircraft and vehicle presence event reporting. And they are not generally configured to determine a forward orientation of a detected aircraft or vehicle and are thus unable to provide notice as to whether an aircraft or vehicle is pointed in a correct direction for safe forward movement. Thus additional information is generally required to augment ground radar system observations, generally through constant visual scanning of affected areas and/or continuous tracking of aircraft and vehicle identity and movements by air traffic controllers or even pilots. And a mistake or lapse by a pilot or controller in acquiring or processing such additional information may fatally compromise ground radar traffic monitoring.
Other ground control systems have been proposed that use global positioning satellite (GPS) transponders located in airplanes in order to enable pilots to correctly locate their airplanes relative to the GPS coordinates of specific runways and other airport areas. However, the use of GPS systems is dependent upon interoperation with third-party satellite systems, as well as ascertaining and deploying detailed airport GPS mappings to airplanes and aircraft systems worldwide, and maintaining airport GPS mappings current in response to any construction projects or other revisions. Thus installation, maintenance, reliability and management costs and issues appear problematic in successfully deploying such GPS systems. Furthermore, such proposed GPS systems are limited to individual aircraft and thus provide little meaningful additional information to airport controllers, who retain significant responsibility for decisions about aircraft movement at the airport.